Car-brake



(No Model.)

' H. N. OOFFIN.

GAR BRAKE No. 401,252. Patented Apr. 9, 1889.

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UNITED STATES PATENT FFICE.

HARRY N. COFFIN, OF PITTSBURG, PENNSYLVANIA.

CAR-BRAK E.

SPECIFICATION forming part of Letters Iatent No. 401,252, dated April 9,1889.

Application filed June 15, 1888.

To all whom it may concern.-

Be it known that I, HARRY N. COFFIN, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful improvements in adevice that has for its object the setting, releasing, and adjusting thebrakes of a car; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it pertains to make and use the same,reference being had to the accompanying drawings, which form a part ofthis specification.

My invention relates to an improvement in a device for setting andreleasing the brakes of a car by means of a worm or perpetual screwoperating in a toothed wheel secured to a cylinder or drum carrying achain connected to the lever of the brakes, so that by revolving theperpetual screw in one direction the chain will be wound around the drumin such a manner as to draw the brakes tightly against the wheels of thecar and there rigidly hold them without relaxation or sudden releaseuntil so required, when by turning the screw in a reverse direction thechain will be unwound, whereby the brakes recede or fall back from thewheels. A projection placed on the outer edge of the drum, together withanother on the wall of the box, acts as a stop, which prevents the drumfrom revolving further than necessary, thereby endangering the safety ofthe working parts, together with certain other details of constructionand combination of parts, as will be more fully described hereinafter.

In the accompanying drawings, Figure 1 is a sectional elevation of myimproved brakeoperating device constructed in accordance with myinvention. Fig. 2 is an end elevation of the same, having the apron orunder side removed therefrom the better to show the working parts. Fig.3 is a sectional plan view of the same.

To put my invention into practice, I construct a strong metallic box, a,of suitable size and form of construction, having a portion of its underside and rear end fitted with Serial No. 277,273. (No model.)

abent plate or apron, b, which prevents dust or other substance fromentering the box a when secured in position beneath the platform of acar. At the forward end of the box a, I arrange in a vertical position aworm or perpetual screw, 0, having a square opening, cl, through itscenter, in which a vertical rod or shaft, f, is placed, projecting somedistance above the floor of the car and provided with a crank or theordinary hand-winch, g. Loosely mounted on a short horizontal shaft, 71,fixed within the metallic box a, is a small gear or toothed wheel, 1',meshing with the perpetual screw 0, and having attached thereto a smallcylinder or drum, 70, having secured thereto one end of a suitablechain, Z, the other end of which is connected to a long rod made fast tothe lever which operates the brakes. To the outer edge of the drum is issecured a short projection, 'm, which, in conjunction with a similarprojection, '11, secured to one side of the box a, limits the rotationof the drum 7; to a single revolution on its axis, which prevents anyexcessive strain on the brake-lever to which the chain Z is attached.Two or more vertical bolts, 0, attached to the box a, serve as a meansfor securing the same beneath the platform of the car. About thecircular opening through which the ver tical rod or shaft f is placed Iform a boss, 1), which prevents dirt or dust from entering the box Cb.By this construction it is an effective device in the hands of abrakeman, it being obvious that 011 turning the screw 0 in one directionthe toothed wheel i will rotate and wind the chain Z about the drum 7:,and thus draw the brakes against the wheels and there hold them, withoutthe use of a clutch or other contrivance, until released by a reversemovement of the screw 0.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, 1s-

A brake-operating device substantially as described, consisting of aninclosing case or shell, at, having a curved apron, b, forming one ofthe sides thereof and leaving an opening for the passage of thebrake-lever chain, a worm-screw, 0, carried by a shaft, f, and

housed Within said case, a fixed shaft, h, a drum and passing throughthe opening in the gear-whee1 fitted loosely on said shaft and casebetween the apron b and one side of the having a drum, a projection, m,fixed to the drum, as and for the purpose described.

peripheryn on the interior of the case or shell HARRY N. OOFFIN. 5 andarranged in the path of the projection m Witnesses:

to limit the drum to a single complete rota- S. P. TOMER,

tion on its axis, and a chain connected to the O. 0. LEE.

